Key Points
- CSI: Crime Scene Improvisation is an unscripted comedy murder mystery where the audience chooses the victim, weapon, and killer.
- The identity of the killer remains unknown to both the cast and the audience until the end of the show.
- Co-creator and performer Sarah Kempton said cast trust and off-stage management are behind the show’s 10-year run.
- Audience members participate as guest investigators by questioning suspects to direct plot twists and evidence reveals.
- The show is touring the UK after sell-out runs at the Edinburgh Festival Fringe and London venues including Wilton’s Music Hall and Underbelly Boulevard Soho.
London (Edinburgh Daily) September 15, 2026 — As reported by Theatre Weekly, co-creator and performer Sarah Kempton revealed how the long-running production CSI: Crime Scene Improvisation constructs a complete whodunnit on stage without a script or predetermined ending. The show relies entirely on crowd participation to launch its premise.
During the opening minutes, audience members shout out the name of the victim, their profession, and the chosen murder weapon. From that moment forward, the cast creates an interconnected narrative filled with suspects, motives, and clues, culminating in a dramatic reveal where the crowd selects the culprit.
Writing for LondonTheatre1, interviewers noted Kempton’s belief that the spontaneous, unrepeatable nature of live improv is what drives audiences to the theatre in an era dominated by on-demand streaming. Kempton stated: “You cannot watch this at home; the danger and excitement and magic of being in the room watching the performers make something is part of it. And you help create it”.
As detailed by The Artiscape, co-creator Lee Apsey and performer Sarah Kempton explained that the production operates as “controlled chaos”. While the plot trajectory changes every single night, the core cast relies on rigorous training and mutual trust to maintain structural coherence. Kempton noted that the secret to a satisfying whodunnit lies in active listening, enabling performers to track minor details thrown out early in the performance and weave them back into the climax.
What Behind-the-Scenes Mechanics Keep a Decade-Old Improv Show Successful?
As reported by Theatre Weekly, Kempton reflected on the group’s journey from their debut at the 2016 Edinburgh Festival Fringe—where they performed on the Free Fringe and had to turn crowds away an hour before showtime—to becoming an award-winning feature across major UK theatre venues. When asked about the longevity of the production, Kempton pointed out an unexpected pillar of their success: business administration.
Kempton stated: “We all genuinely enjoy performing with each other and entertaining each other… We also hit gold off stage because we work together really well on the admin side of running the group. I’ve been part of other really great groups where it’s the off-stage work that leads the show to fizzle, so we were incredibly lucky that this gelled as well off stage as it did on”.
As observed in a review by Everything Theatre, the show’s format deliberately turns the audience into an active participant—often dubbed “Sergeant Derek” or “Detective Cliff”—who interrogates suspects during dedicated cross-examination scenes. Reviewers from Theatre & Tonic noted that halfway through the one-hour performance, the cast recaps the established evidence, giving the audience a clear footing before they cast their final votes on who committed the crime.
Kempton, who is also an accomplished voiceover actor voicing characters in video games such as Warhammer and Tainted Grail, stated in interviews with Theatre Weekly that performing live improv offers a vital creative balance to working in isolated voice booths. She noted that voice acting skills assist in character building on stage, while the spontaneity of improv brings extra playfulness to her commercial and audio drama work.
Background of CSI: Crime Scene Improvisation
CSI: Crime Scene Improvisation was founded over twelve years ago by Lee Apsey and Sarah Kempton. The production was created to merge traditional classic whodunnit tropes—made famous by Agatha Christie and 2000s crime television shows—with fast-paced narrative improv. Over its operational history, the troupe has expanded its ensemble to include performers such as Nicola Lucey, Steve Bond, Michael Kunze, James Cann, and Kayleigh Cassidy.
The show has gathered multiple industry accolades, including Best Improvisation at the Leicester Comedy Festival 2023 and the Comedy Award at the Colchester Fringe 2024. Following multi-year sell-out runs at the Edinburgh Festival Fringe, the show regularly tours regional UK venues like Taunton Brewhouse alongside prominent London residencies at Wilton’s Music Hall and Underbelly Boulevard Soho.
Predictions: How Will the Growth of Interactive Improv Impact Theatre Audiences?
The continued rise and mainstreaming of interactive, unscripted productions like CSI: Crime Scene Improvisation signals a permanent shift in theatregoers’ habits. As digital screen fatigue increases, live audiences are increasingly prioritizing events that offer active agency over passive observation.
Shift in Audience Expectations
Theatregoers attending unscripted comedy productions are transitioning from passive viewers into co-creators. Because no two performances of CSI: Crime Scene Improvisation can ever be duplicated, audiences gain a sense of exclusive ownership over the specific show they witness. This dynamic fosters higher audience retention and repeat attendance, as patrons return to test different narrative setups and murder scenarios.
Commercial Impact on Independent Theatre Groups
The administrative and artistic model established by Kempton and Apsey provides a sustainable blueprint for independent comedy troupes. By maintaining low overheads—using minimal stage sets consisting of basic props or simple seating—the production minimizes financial risk while maximizing adaptability across venues ranging from pub theatres to historic music halls. This model is likely to inspire emerging UK improv groups to focus as heavily on internal management structures as on performance skills to ensure long-term commercial survival.
